This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Color perception is one of the key features of our visual system that permits an appropriate interaction with our environment. Hence, the investigation of neuronal mechanisms forming the basis for color vision is one of the major goals in the field of retinal neuroscience. Processing of color signals starts already at the level of the retina, where the light responses of the different cone photoreceptor types are 'compared'and modulated. Among other mammalian species, humans and many of the non-human primates show one of the most highly developed systems for color vision. This system is based on three chromatically tuned cone types (red, green, and blue). Retinal ganglion cells receive and process the cones'signals and send them to higher visual centers of the brain. Up to date, research on color-coded ganglion cells of the primate retina focused on two distinct cell types: the midget ganglion cell (red-green processing) and the small bistratified ganglion cell (blue-yellow processing). However, further primate ganglion cell types have been discovered, which showed color-opponent responses to chromatic light stimuli. Though a detailed analysis is still missing, one can expect that these cell types also play a fundamental role in primate color vision. These cell types include the large bistratified ganglion cell, which is supposed to show blue-yellow opponent responses, similar to what has been observed in the small bistratified cell. The aim of this project is to provide a comprehensive study on the anatomical and physiological properties of the large bistratified ganglion cell in the primate retina. The main focus will be directed at the analysis of the neuronal pathways and the synaptic mechanisms, underlying the chromatically tuned responses of this cell type.